Denso Corporation

Oki Electric Industry Co., Ltd.

Denso It Laboratory, Inc.

Chiharu Yamano

Kazuma Natsume

Yuu Watanabe

Koichiro Suzuki

Mai Sakamoto

Yasuyuki Miyake

Gaku Takano

Yuichi Shiraki

Hideki Shirai

Yasushi Sakuma

Mitsutoshi Morinaga

Takuya Takayama

Hiroto Nakatani

Koji Shimizu

Kento Nakabayashi

Kiyoki Sekine

Jingo Adachi

Norikazu Ikoma

A tracking apparatus which tracks a target includes a predilection unit, correction unit, and updating unit. The prediction unit predicts the state distribution of the target at a specific time. The correction unit, for at least one observation point of the target, that is observed at the specific time, uses a likelihood function to define a degree of certainty of the state distribution predicted by the prediction unit, and corrects the likelihood function depending on the number of observation points. The updating unit updates the state distribution at the specific time based on the likelihood function corrected by the correction unit.

Tracking apparatus, tracking method, and non-transitory storage medium storing tracking program

An acquiring unit acquires, for each of reflection points detected by a radar device, reflection point information including a horizontal angle, a vertical angle, and a relative speed. A converting unit converts each of the reflection points into three-dimensional coordinates. An extracting unit extracts stationary reflection points from the reflection points. An estimating unit uses a relational expression established among unknown parameters including a traveling direction vector and a moving speed of a moving body, three-dimensional coordinates of each of the stationary reflection points, and a relative speed of the stationary reflection point, to estimate the known parameters. A calculating unit determines an axial misalignment angle from the estimated unknown parameters.

Axial-misalignment estimating device

A technique of estimating a surrounding environment with higher accuracy from observation data obtained by using sensing equipment is disclosed. According to the technique, a certain pixel in an observation data space which includes the observation data obtained by a sensoris sampled. With regard to the sampled pixel, a grid-unspecified logarithm-likelihood ratio indicating whether a received signal is a signal reflected from a detected object is calculated from an intensity value of the received signal, and a distribution function of an angle indicating the degree of dispersion centering on an azimuth angle is calculated. Then, the product of the grid-unspecified logarithm-likelihood ratio and the distribution function is calculated and thereby a calculation for updating an occupation probability of the object is performed across a plurality of grids in an occupancy grid map by using a value obtained by dispersing the likelihood using the distribution function.

Surrounding environment estimation device and surrounding environment estimating method

A radar apparatus generates a spectrum distribution where frequencies in a beat signal are associated with intensities of respective frequency components. Based on a plurality of spectrum distributions generated over a predetermined number of measurement cycles prescribed in advance, the radar apparatus generates a reflection intensity distribution where frequencies are associated with road surface reflection intensities of the radar wave from a road surface at each frequency. In the reflection intensity distribution, the radar apparatus detects an intensity peak indicating a frequency that maximizes the road surface reflection intensity. Based on the detected intensity peak, the radar apparatus determines at least whether or not the radar apparatus is in an axis deviation state that is taken as a state where a reference axis of the radar apparatus has an inclination of not less than a prescribed angle in a vehicle height direction relative to a horizontal axis prescribed to a vehicle.

Radar apparatus, method for inspecting axis deviation thereof, and computer-readable recording medium with program recorded thereon

A signal processing unit in a radar device calculates a change amount Y (=log(P)&#x2212;log(Pb)) between a power P of a current arrival echo and a power of a previous arrival echo arrived before an observation period T. A memory unit in the radar device stores, every type of objects, a probability distribution of the change amount Y calculated from the arrival echo from the object. On the basis of the calculated change amount Y and the probability distribution, the signal processing unit determines a probability Pr to obtain the change amount Y every type of object, and determines that the object having the maximum probability Pr is the object which transmits the current arrival echo.

Radar device

A sampled beat signal RD is split into a plurality of short-time data SD in the time direction, for each of antenna elements. Interference component frequency of an interference wave is detected from a frequency spectrum of the short-time data SD. A digital beam forming process is performed for the interference component frequency of the interference wave to extract a peak of the electrical power of an azimuth direction and estimate an absolute value of an incoming direction of interference components. Based on the absolute value of the incoming direction of the estimated interference components, a filter for suppressing the interference components is operated to suppress the interference components.

Electronically scanned radar system

A FMCW-type radar device generates snapshot data from a beat signal that represents a received condition of the radar device every modulation period. Auto-correlation matrices generated by the snapshot data every modulation period are averaged every set of plural periods. The radar device calculates the target azimuth of a target object such as a preceding vehicle based on the averaged auto-correlation matrix based on MUSIC (MUltiple SIgnal Classification) method. This averaging is performed by weighting average based on an amount of mixed noise (or an interference amount) contained in the snapshot data in each modulation period. A weighting coefficient to be applied to the auto-correlation matrix in each modulation period is set to a value corresponding to the amount of mixed noise, namely, the interference amount of this modulation period. The weighting coefficient becomes large when the interference amount is small, and on the other hand, becomes small when it is large.

A plurality of array antenna elements are divided in terms of a set constituted of an optionally selected L number of groups. The spaces between the array antenna elements are determined by obtaining a greatest common divisor of the set as a greatest common divisor of inter-group element spaces, the set having, as components, greatest common divisors of inter-element spaces of the individual L number of groups in the set, obtaining a greatest common divisor of inter-group element for every number L equal to or less than the maximum number of incoming waves by changing the number L of group components, and allowing a direction not to be caused in the radar scanning region by a number equal to or more than L+1, on the basis of the greatest common divisor of inter-group element spaces for every number L of group components, the direction being linearly dependent on an incoming wave corresponding to the greatest common divisor of inter-group element spaces.

Electronically scanned radar system and receiving antenna

A technology for providing an arrival direction estimation apparatus which can greatly reduce the calculation amount in spectrum calculation and can perform precise direction estimation without setting short frequency division in spectrum calculation is disclosed. According to the technology, there is provided the arrival direction estimation apparatus including an antenna, a complex digital signal converting means, a real number correlation matrix calculating means, a real number weight matrix calculating means, a spectrum calculating means, and a spectrum peak detecting means, wherein the spectrum calculating means has a real number matrix storing means which stores a real number matrix, a multiplying means which multiplies part of elements of the real number matrix by part of elements of a real number weight matrix, a result storing means which stores the multiplication processing result, a calculating means which performs at least one or more processing of matrix element inversion processing and matrix element sign change processing for the stored processing result, an adding means which adds the processing result by the calculating means, part of the processing result stored in the result storing means, and part of the elements of the real number weight matrix, and a spectrum calculating means which calculates a spectrum with the use of the processing result.

Arrival direction estimation apparatus

In a FM-CW or CW radar apparatus, when interference components are contained in channel signals obtained as beat signals from array antenna elements of respective channels, and the interference components result from directly receiving transmitted CW radar waves from an external source, phase shifting is applied to each of the channel signals to shift respective phases of the interference components of the respective channels to a condition corresponding to reception of interference waves from a predetermined direction. The interference components are then eliminated, and reverse phase shifting is applied to restore remaining components of the channel signals to their original phase condition.

Radar apparatus enabling simplified suppression of interference signal components which result from reception of directly transmitted radar waves from another radar apparatus

An electronic scanning radar apparatus has a cutting portion for cutting receiving data which is comprised of N numbers of data for each channel into two more short time data having M (&#x3c;N) numbers of data in a time direction for each channel, an inverse matrix estimator for computing and estimating an inverse matrix of the time series correlation matrix from the short time data, and a phase information producing portion for computing CAPON phase information out of the estimated inverse matrix of the time series correlation matrix in order to detect a distance, an azimuth and a relative speed of a target on the basis of a computed CAPON phase information.

Electronic scanning radar apparatus

A target detecting apparatus mounted on a vehicle has an electronically agile radar detecting a beat signal indicating a difference in frequency between transmission and reception signals and producing a time series of N reception data from the beat signal, a determining unit determining search areas placed at different ranges of distance from the vehicle while considering a running state of the vehicle and determining a data length for each search area, an extracting unit extracting (N&#x2212;M+1) time series of short time data, respectively, having the data length corresponding to M reception data from the N reception data for each search area, a producing unit producing phase information from the short time data for each search area, and a detecting unit determining a target distance and a target bearing from the phase information and detecting a target from the target distance and the target bearing.

Target detecting apparatus using electronically agile radar

A radar signal processor is disclosed having an observation mechanism for receiving a reflected wave from a target and for outputting a predetermined observation signal. The processor extracts a distance component corresponding to a distance from each observation signal. The processor further collects the respective distance components and computes an estimated value of a corresponding correlation matrix with a forgetting factor as a parameter using a method for estimating correlation matrix with exponential smoothing. The processor further estimates the presence or movement state of the target on the basis of the respective estimated values of the correlation matrices and outputs the computed values.

Radar signal processor

A sampled beat signal is cut out into two or more short time data in a time direction concerning each antenna component. From a frequency spectrum of the short time data, an interference element frequency of an interference wave is detected. From the interference element frequency of the interference wave, two or more candidates of the frequency before aliasing of the interference wave are produced, and phase correction is executed on each candidate. Digital Beamforming is executed on the corrected frequency so as to extract maximum peaks of the power of an azimuth direction, and the frequency candidate showing the maximum peak power is selected and the arrival azimuth of the interference element is estimated. A filter for suppressing the interference element is applied on the short time data from the estimated arrival azimuth of the interference element so as to suppress the interference element.

A radar signal processor has observation means for outputting a predetermined observation signal from a reflected wave, means for extracting an observation signal component concerning a target from the observation signal, means for computing a sample correlation matrix showing a correlation characteristic between the observation means from the observation signal components, means for estimating power of the reflected wave from the sample correlation matrix, and an array response matrix which is comprised of response vectors of the reflected waves. When estimating the power, an adjacent azimuth array response matrix having only the reflected waves of a predetermined arrival direction which power is to be estimated and the reflected waves of an azimuth adjacent to the reflected wave as elements is determined so as to estimate the power of the reflected wave.

Growing community of inventors

Tokyo, Japan

Chiharu Yamano