Abstract: Disclosed is a radar apparatus which receives a transmitted signal reflected from an object by switching between a plurality of antennas, wherein the plurality of antennas are divided into a plurality of groups, and at least one of the plurality of antennas contained in each of the groups is a common antenna.

Abstract: In a radar apparatus for automobiles for transmitting a radio wave, receiving a radio wave reflected from an object and measuring a rate of the object, a digital signal processor has at least two operation modes, a normal operation mode and a low energy consumption mode, and has a function of switching between the operation modes of the digital signal processor in accordance with a signal supplied from a counter (judgement unit) for judging whether a received signal satisfies predetermined conditions. The radar apparatus can reduce consumption power when necessary.

Abstract: Disclosed is a transmit-receive FM-CW radar apparatus which switches between transmission and reception by time division control, wherein amplifiers capable of controlling gain are provided in a transmitter signal path and a receiver signal path, respectively, and wherein the gain in the leading edge portion of a receive timing interval or the gain in the trailing edge portion of a transmit timing interval is suppressed by controlling the gain of the amplifier provided in the receiver signal path or the gain of the amplifier provided in the transmitter signal path, respectively.

Abstract: The intrusion detection system comprises a pair of narrow-beam microwave detectors exploiting Doppler effect and independently operating. A processing unit analyses the signals received by both detectors versus time and Doppler frequencies and amplitude. Analysis of such data allows detecting an actual intrusion. The processing unit also analyses the steady presence of the radio-frequency signal at each detector, to ascertain possible failures or tampering of the system.

Abstract: An FM-CW radar system comprises a modulating signal generating means for changing a modulating signal to be applied to a FM-CW wave, a calculating means for calculating a distance or relative velocity with respect to a target object by performing processing for detection by fast-Fourier transforming a beat signal occurring between a transmitted signal and a received signal, and a control means for determining a detection range based on the calculated distance, and for performing control to change the modulating signal, wherein the modulating signal is changed by changing one parameter selected from among a modulation frequency, a triangular wave frequency, and a transmit wave center frequency. The detection range is set to a distance obtained by adding a prescribed distance to the shortest distance detected, or to a distance obtained by subtracting a prescribed distance from the distance of a fixed object.

Abstract: Disclosed is a Doppler shifted radar apparatus for correct target identification with respect to surveillance of moving vehicles. More particularly, an improved radar detection system using two or more continuously transmitted frequencies is used. The multiple frequencies are directed toward target vehicles whereby the phase difference of the two or more reflected Doppler signals is calculated and subsequently used to accurately determine a target range, thereby displaying the closest vehicle and closest vehicle speed. Vehicle speed is determined with use of the standard Doppler frequency shift. The next closest and/or next faster vehicle speed can also be easily determined.

Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.

Abstract: An adaptive cruise control system is provided for tracking a target vehicle through a curve. The adaptive cruise control system tests whether the target vehicle is traveling along the curve or whether the target vehicle is changing lanes. The test includes monitoring a change in travel directions between the target vehicle and the adaptive cruise control vehicle. In one embodiment, the test monitors a change relative velocity versus azimuth angle.

Abstract: The invention relates to the input of speed limiting values into a speed limiter in a vehicle. The speed limiting value which is to be complied with is set by activating a key (7) on an input device (8) one or more times. That speed limiting value of the predefined speed limiting values which is the next highest in relation to the current speed of the vehicle is selected. If the current speed of the vehicle is higher than the highest predefined speed limiting value, the speed limiter is deactivated or the speed of the vehicle plus a speed difference is accepted as the speed limiting value. In exceptional situations, the speed limiter can be temporarily suspended, it being possible for an exceptional situation to be, in particular, the upward transgression of the predefined speed limiting value or a rapid depression of the gas pedal.

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 suppresses a dc component so as to improve the precision in processing a signal that belongs to a low-frequency band. The radar comprises a mixer that mixes a transmitted signal and a received signal, and an A/D converter that analog-to-digital converts an output signal of the mixer. The radar further includes: a removing unit that removes a dc voltage component by subtracting a predetermined removal voltage value from output data of the A/D converter; and an analyzing unit that Fourier-transforms data, which has the dc voltage component removed therefrom by the removing unit, so as to analyze the data.

Abstract: Disclosed is a radar apparatus equipped with a function for detecting an abnormality of modulation width. Distance rt2 at time t2 is calculated from the values of the distance Rt1 and the relative velocity Vt1 measured at time t1 and the elapsed time t2−t1, and the difference relative to the actual measured value Rt2 is compared with a threshold value C1. If the difference relative to the actual measured value exceeds the threshold value C1, the modulation width is judged to be abnormal.

Abstract: A distance and speed measuring method and a radar signal processing apparatus using the method are provided which are capable of obtaining highly reliable measurement results while reducing the number of false targets and undetectable targets, by obtaining the relative distance and the relative speed of each target based on the frequencies of a beat signal of up (or down) phase alone through the use of information in a time series direction of the frequencies of the beat signal of up (or down) phase.

Abstract: The invention relates to a speed limiter in a vehicle. The speed limiting value which is to be complied with is set by activating a key (7) on an input device (8) one or more times. That speed limiting value of the predefined speed limiting values which is the next highest in relation to the current speed of the vehicle is selected. If the current speed of the vehicle is higher than the highest predefined speed limiting value, the speed of the vehicle plus a speed difference is accepted as the speed limiting value. In exceptional situations, the speed limiter can be temporarily suspended, it being possible for an exceptional situation to be, in particular, the upward transgression of the predefined speed limiting value or a (rapid) depression of the gas pedal.

Abstract: 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.

Abstract: The system comprises: detector devices (1) operable to provide electrical signals indicative of the relative distance and relative speed of the motor vehicle (V) with respect to a fixed or moving obstacle (O) ahead, and a processing and control unit (ECU) connected to such detector devices (1) as well as to brake actuators (2-4) and arranged to cause activation of the brake actuators (2-4) to effect automatic emergency braking of the motor vehicle (V) when the relative distance between the motor vehicle (V) and an obstacle (O) ahead lies between a first predetermined limit value (dF) equal to the minimum value at which it is still possible to avoid collision by braking and a preselected intermediate value (dE) comprised between said first limit value (dF) and a second limit value (dEcrit) which is less than the said first limit value (dF) and is equal to the minimum relative distance value at which it is still possible to follow a path which avoids the obstacle (O), or when the relative distance (dR) becomes

Abstract: An FM-CW radar apparatus capable of detecting a stationary object, in particular, an overbridge, located above the road ahead in a simple manner uses a traveling wave antenna as a transmitting antenna, and includes a means for varying, in upward and downward directions the projection angle of a combined beam pattern of a transmitted wave radiated from the traveling wave antenna, and an overbridge is detected by varying the projection angle of the combined beam pattern in the upward direction using the varying means. Further, a phase shifter for varying the projection angle of the beam pattern in upward/downward directions by controlling the phase of the radio wave to be transmitted or received is provided on either a transmitting antenna or a receiving antenna or on a transmitting/receiving antenna, and an overbridge is detected by controlling the phase shifter and varying the projection angle of the beam pattern in the upward direction.

Abstract: A double side band diplex linear frequency modulated superimposed radar system determines the range of targets as a function of the amplitude variation of reflected target Doppler signals. The present invention includes a real radar system that accurately determines the range of fading targets and the magnitude of the velocity of the targets. The present invention also includes a complex radar system that determines the relative velocity of targets in addition to the range of targets. The present invention also includes a real radar system having BPSK modulation. The selection of BPSK modulation enables or facilitates. the implementation of a portion of the system in digital form.

Abstract: A method for processing pulsed-Doppler radar signals to detect a target includes transmitting radar signals from a radar system according to a predetermined frequency technique including signals having frequency diversity, receiving signals within a frequency band, including a target return signal having a frequency indicative of the velocity of the target, and transforming the target return signal using a Fourier Transform having a variable frequency scale.

Abstract: A stationary object detection method for a scanning radar wherein, of peaks generated based on a radar signal reflected from a target, peaks having substantially the same frequency are grouped together, and a decision is made as to whether or not the frequency of the grouped peaks is equal to/higher than a predetermined value, and wherein if the peak frequency is equal to or higher than the predetermined value, then a decision is made as to whether or not the number of grouped peaks is equal to or greater than a predetermined number and, if the number of peaks is equal to or greater than the predetermined number, it is decided that the target is an overhead bridge candidate or an overhead bridge.

Abstract: A vehicle control apparatus includes an obstruction detection unit for measuring a headway distance until an obstruction existing ahead of the vehicle by means of a radar device, a unit for performing vehicle control or alarm control on the basis of the headway distance, a unit for detecting detection performance of the obstruction detection means in a vehicle in which the obstruction detection unit is used to perform two or more controls containing the vehicle control or alarm control, and a unit for controlling to stop operation of the vehicle control or alarm control in accordance with the detection performance individually.

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.

Abstract: A transmitted signal and a received signal are combined and the combination is expected to determine whether or not a target signal is present. Either the transmitted signal or the received signal is combined with an auxiliary signal containing a range of frequencies corresponding to an anticipated Doppler shift, so that an output of the combined transmitted and received signal will be present only if a target signal exhibiting a Doppler shift within the anticipated range is present. The auxiliary signal preferably comprises finite-duration signal portions of different types so as to provide a substantially uniform frequency response throughout the selected range.

Abstract: In an FM-CW radar system, regarding peaks appearing in the frequency spectrum of a beat signal in an FM-CW radar, groups of consecutive peaks in beam bearings within a predetermined frequency difference are regarded as being caused by reflected waves from a single target, and based on a combination of a peak group in an up-modulating interval and a peak group in a down-modulating interval, a relative distance to a target and its relative speed are determined.

Abstract: 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.

Abstract: System and method for detection and tracking of targets, which in a preferred embodiment is based on the use of fractional Fourier transformation of time-domain signals to compute projections of the auto and cross ambiguity functions along arbitrary line segments. The efficient computational algorithms of the preferred embodiment are used to detect the position and estimate the velocity of signals, such as those encountered by active or passive sensor systems. Various applications of the proposed algorithm in the analysis of time-frequency domain signals are also disclosed.

Abstract: In a single-antenna time division control type FM-CW radar, an amplifier is provided in each signal path in a transmitting system and a receiving system, and the amplifier provided in the transmitting system and the amplifier provided in the receiving system are operated alternately in synchronism with transmit and receive timings, to perform switching between transmission and reception. The operation of the amplifiers is controlled by controlling the gain of each of the amplifiers. This configuration provides enhanced isolation between the transmitting and receiving systems, and prevents transmitting power from leaking into the receiving system through a transmit-receive switching section.

Abstract: An in-vehicle pulse radar device includes: an oscillator that generates an electromagnetic wave; a transmission amplifier that transmits the electromagnetic wave generated by the oscillator toward a target substance; an antenna that receives the reception electromagnetic wave reflected by the target substance to output data; reception amplifiers; a reception antenna; an A/D converter; and a signal processing device that pre-sums data which is sampled on the basis of the data from the A/D converter for each of distance gates, subjects the pre-summed data which is a result of the pre-summing process to an FFT process, and obtains a distance between a subject vehicle and the target substance and a relative speed therebetween in accordance with the spectrum frequency and the amplitude information which are a result of the FFT process.

Abstract: The invention concerns a passive radar receiver for a received orthogonal frequency division multiplex-type signal consisting of symbol frames each emitted on coded orthogonal carriers. After formatting the received signals into digital symbols (S1 S1), a filtering circuit (2) eliminates by subtraction or using a covariance matrix, in the symbol signal at least unwanted signals with null Doppler effect so as to apply a filtered signal (X′) including essentially signals backscattered by mobile targets to a Doppler-distance correlator (4).

Abstract: A device for a radar system, the device being supplied with the received signals of at least two receiving antennas as input signals, and in which the output signals of this device are supplied to at least one unit for evaluating the received signals which includes at least two evaluation channels. Different input channels are allocated to the at least two evaluation channels as a function of supplied control signals.

Abstract: A radar device includes a mixer that mixes an output of a transmit antenna 4 and an input of a receive antenna 6, an LPF 8, an A/D converter 9 that samples an output signal of the LPF 8 and subjects the sampled signal to A/D conversion, an FFT processing device 10 that subjects the converted signal to high-speed Fourier transformation, an aliasing discriminating/correcting device that discriminates a signal having a frequency component where aliasing occurs from a result by the FFT processing device 10 and corrects the signal to a signal of a normal frequency component where no aliasing occurs to obtain a distance and relative velocity data of the object, and a target object selecting device that selects necessary data from the distance and relative velocity data of the object which are obtained from the aliasing discriminating/correcting means.

Abstract: An adaptive cruise control (ACC) system (10) for a host vehicle (12) is provided. The ACC system (10) includes a forward-looking sensor (18) generating a range signal corresponding to a distance between the host vehicle (12) and a target vehicle. The forward-looking sensor (18) also generates a range rate signal corresponding to a rate that the distance between the host vehicle (12) and the target vehicle is changing. A controller (20) is electrically coupled to the forward-looking sensor (18). The controller (20) maintains a preset headway distance between the host vehicle (12) and the target vehicle, when the host vehicle velocity is less than about 40 KPH, by adjusting the host vehicle velocity in response to the range signal and the range rate signal. A method for performing the same is also provided.

Abstract: 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.

Abstract: The present invention relates to a monitoring device (1) with a transmitter unit (2) and a receiver unit (3) for monitoring an area.

Abstract: The invention relates to a method for adaptive target processing in a vehicle radar, the targets in the surroundings being detected by speed and place in the standard mode of the radar sensor, after detection of the targets in the standard mode it is being changed over to a precision mode, in which the distance measuring range of the radar sensor is adapted to the target surroundings detected in the standard mode. In accordance with the present invention the measuring accuracy and/or resolution regarding speed is increased by increasing the time of observation within the distance measuring range adapted to the target surroundings.

Abstract: An automobile radar which serves to provide data for cruise control or other systems in a host vehicle, comprising means for measuring radar boresight misalignment by detecting the presence of apparent variations in the spacing of stationary objects from the direction of motion of the host vehicle and utilising such detection to compensate for any misalignment.

Abstract: A radar device precisely detects a target in short time intervals by detecting a true peak frequency with high accuracy via a calculation which does not require a large amount of computation. A discrete frequency spectrum of a beat signal multiplied by a window function is determined, and values of signal strength at two discrete frequencies which are, respectively, higher and lower than a peak frequency of the discrete frequency spectrum of the beat signal and which are adjacent to the peak frequency. The frequency difference between the discrete peak frequency of the beat signal and the peak frequency of the window function is then determined from the ratio between the values of signal strength at those two discrete frequencies adjacent to the peak frequency. Thus, the true peak frequency of the beat signal is determined with a high frequency resolution.

Abstract: In a method for HPRF-radar measurement of the range and Doppler frequency of at least one target, a transmit signal is generated which consists of two pulse sequences that are interleaved on a pulse to pulse basis, and have the same pulse repetition frequency PRF and the same transmit frequency. The pulses of a first one of the two pulse sequences have a linearly increasing phase value with a fixed phase difference &phgr;1n (greater than zero) from pulse to pulse with &phgr;1n≧0, while the pulses of the second pulse sequence have a linear increasing phase value with a fixed phase difference &phgr;2n which differs from &phgr;1n. The two received base band signals of each individual pulse sequence are Fourier transformed, and the amplitude peaks of the resulting two Fourier spectra are determined.

Abstract: An outdoor microwave transceiver intrusion detector that alternately transmits pulses of RF energy at two different frequencies and uses range and direction of travel information derived from the phase of the two Doppler responses to optimize the signal processing and apply range dependent thresholds. The time delay between the onset of the transmitted pulse and the sample of the Doppler response is controlled to provide an accurate range cutoff. The two frequencies are selected so that the difference in phase of the Doppler response at the two frequencies increases from zero to ninety degrees as the target goes from the Transceiver to the maximum range. Digital signal processing is used to measure the difference in phase of the two Doppler responses and translate this information into location of the target. The location information is used to create a number of range bins.

Abstract: Radar systems are used for ascertaining the range to at least one reflecting object present in an observation area and/or for ascertaining the speed of the at least one reflecting object. Such a radar system emits into the observation area successive transmitter pulses having a determined pulse duration, with a determined pulse-repetition frequency as a transmitted signal. The system receives transmitted pulses reflected by the at least one reflecting object of the transmitted signal as a received signal. The disadvantage thereby is, that the method has high signal dynamics, which has an unfavorable effect on the price of the circuit components required for the signal processing. The new method for operating a radar system shall be performable with cost effective means.

Abstract: A radar system includes a transmitting/receiving unit, having a voltage controlled oscillator, for repeatedly transmitting a triangular transmission signal including a frequency-gradually-rising up-modulation interval and a frequency-gradually-dropping down-modulation interval and for receiving a reception signal including a reflected signal from a target, a frequency analysis unit, a data storing unit for storing time-varying characteristics of input values to a D/A converter that monotonically change an oscillation frequency of the voltage controlled oscillator with time, in the form of data concerning an expression representing the time-varying characteristics, and a data processing unit for determining the input values to the D/A converter with reference to the data. At least one of the relative distance to the target and the relative speed of the target is detected based on a beat signal during the up-modulation interval and the beat signal during the down-modulation interval.

Abstract: A method for interrupting a speed control or vehicle to vehicle ranging of a motor vehicle's control system, in which the system passes over into the standby mode with the aid of a predefined algorithm after the switching-off of the active control. A linear function for the acceleration in the case of propulsion as well as the braking case is provided as the algorithm. In an alternative embodiment using a step function having appropriately designed steps is provided. This achieves in an advantageous manner a soft transition from active control operation to the standby mode.

Abstract: An FM-CW radar processing system pairs up peaks obtained by fast-Fourier transforming a beat signal occurring on an up portion and a down portion of a triangular-shaped FM-CW wave, calculates a distance or relative velocity with respect to a target object based on the peak signal in the up portion and the peak signal in the down portion obtained by the pairing, and compares the distance or relative velocity, obtained after changing the modulating signal for the FM-CW wave, with the distance or relative velocity obtained before changing the modulating signal. If the distance or relative velocity differs before and after changing the modulating signal, the pairing is judged to be mispairing.

Abstract: The present invention relates to a radar device and, particularly, to a radar device mounted on a vehicle to be used for a collision alarm and the like. The invention provides a radar device that has a unit for removing the FMAM noise without lowering the signal detection sensitivity. The radar device transmits a frequency modulation signal by switching the frequency modulation signal with a first switching signal, receives a signal reflected from a target object, switches the reception signal with a second switching signal, mixes the switched reception signal with the transmission signal, and further mixes the mixed signals with a third switching signal thereby to obtain a beat signal. The radar device obtains a distance to the target object and a relative speed of the target object from the beat signal.

Abstract: The invention detects a ghost occurring due to mispairing, reflections from a wall, or the like, and improves the ability of a radar to track targets when actual relative velocity changes by more than a certain value. If a stationary target is present within a prescribed region centered about a moving target, the stationary target is excluded from output data by determining it as being a target resulting from mispairing due to the detection of guardrail posts or similar structures. Further, a moving target that is expected to collide with an eligible target is also excluded from the output data by determining it as being a target resulting from mispairing due to the detection of a target having many reflecting points. For a moving target showing an unlikely relative velocity, pairing with some other peak is attempted by determining the moving target as being a target resulting from mispairing due to the detection of a plurality of moving targets moving in the same direction.

Abstract: Disclosed is a method of storing data for temporarily storing a plurality of detected data in a data buffer or the like included in a radar used for a vehicle. The radar detects signals reflected from a plurality of target objects so as to obtain a plurality of detected data, and detects the presence of the plurality of target objects on the basis of the plurality of detected data.

Abstract: A method for calculating a center frequency and a bandwidth for a radar doppler filter is herein described. The center frequency and bandwidth are calculated to provide radar performance over varying terrain and aircraft altitude, pitch, and roll. The method includes receiving an antenna mounting angle, a slant range, and velocity vectors in body coordinates, calculating a range swath doppler velocity, a track and phase swath bandwidth, and a phase swath doppler velocity. The method continues by calculating a range swath center frequency based on the range swath doppler velocity, calculating a phase swath center frequency based on the phase swath doppler velocity, and calculating a level and verify swath bandwidth based upon the track and phase swath bandwidth.

Abstract: A method for exciting an antenna with a waveform having a burst width and pulse width scaled proportionately with a selected range scale and a temporal filter to address any ambiguities in range resulting from the transmission of a signal in accordance with the novel waveform. The inventive filtering method includes the step of scanning a beam including a plurality of pulses of electromagnetic energy. The step of scanning the beam includes the step of outputting a beam excited by a waveform having a burst width and pulse width scaled proportionately with a selected range scale. Reflections of these pulses are received as return signals. The returns are processed to extract range in range rate measurements. The range and range rate measurements are compressed to form a plurality of range bins. The pulses are selectively weighted to reduce sidelobes resulting from a subsequent Fast Fourier transform (FFT) operation.

Abstract: An FMCW radar is provided which may be employed in automotive anti-collision or radar cruise control systems. In a distance measuring mode, only one of channels is used to sample a beat signal continuously, thereby allowing a sampling frequency to be increased up to Nc times that in an azimuth measuring mode and a sweep time in which a transmit signal sweeps in frequency upward and downward cyclically to be minimized. This causes half the sampling frequency to be higher than a frequency component arising sufficiently from a distant target present outside a preset radar range, thereby eliminating an error in detecting the distant target as being located inside the preset radar range.

Abstract: System and method for detection and tracking of targets, which in a preferred embodiment is based on the use of fractional Fourier transformation of time-domain signals to compute projections of the auto and cross ambiguity functions along arbitrary line segments. The efficient computational algorithms of the preferred embodiment are used to detect the position and estimate the velocity of signals, such as those encountered by active or passive sensor systems. Various applications of the proposed algorithm in the analysis of time-frequency domain signals are also disclosed.