RADAR DEVICE, CALIBRATION SYSTEM AND CALIBRATION METHOD
First Claim
1. A radar device comprising:
- a transmitting antenna which transmits radar waves toward an object in front of the radar device;
a receiving antenna comprising a plurality of antenna elements, each antenna element receiving arrival radar waves reflected by the object; and
a signal processing unit which estimates at least an arrival azimuth and an object distance on the basis of information of the arrival radar waves received by the antenna elements, and generates object information which contains the arrival azimuth of the arrival radar wave and the object distance per object by which the radar wave is reflected, the arrival azimuth is an azimuth of the arrival radar waves received by the antenna elements, and the object distance is a distance between the radar device and the object,wherein the signal processing unit comprises;
an eigenvalue calculation means for calculating a correlation matrix which indicates a correlation between received signals in each pair of the antenna elements in the receiving antenna, and calculating an eigenvalue of the correlation matrix;
a ratio calculation means for calculating an eigenvalue ratio which indicates a ratio between the maximum eigenvalue in the eigenvalues calculated by the eigenvalue calculation means and a comparison eigenvalue which is an eigenvalue other than the maximum eigenvalue; and
an environment judgment means for judging whether or not a current environment is, in which the radar device is located, suitable for the calibration of the radar device on the basis of the eigenvalue ratio calculated by the eigenvalue calculation means.
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Accused Products
Abstract
In an environment inspection mode of a calibration system, a radar device executes a signal analysis process to calculate an eigenvalue ratio of each comparison eigenvalue. The eigenvalue ratio has a small value when a pair of eigenvalues corresponding to arrival radar waves has a strong correlation. On the other hand, the eigenvalue ratio has a large value when the eigenvalue ratio is calculated between an eigenvalue and thermal noise. When there is no eigenvalue which is not more than a reference threshold value, the radar device indicates a notice that the current environment is suitable for the calibration of the radar device. On the other hand, when there is presence of at least one eigenvalue of not more than the reference threshold value, the radar device indicates a notice that the current environment is unsuitable for the calibration of the radar device.
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Citations
10 Claims
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1. A radar device comprising:
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a transmitting antenna which transmits radar waves toward an object in front of the radar device; a receiving antenna comprising a plurality of antenna elements, each antenna element receiving arrival radar waves reflected by the object; and a signal processing unit which estimates at least an arrival azimuth and an object distance on the basis of information of the arrival radar waves received by the antenna elements, and generates object information which contains the arrival azimuth of the arrival radar wave and the object distance per object by which the radar wave is reflected, the arrival azimuth is an azimuth of the arrival radar waves received by the antenna elements, and the object distance is a distance between the radar device and the object, wherein the signal processing unit comprises; an eigenvalue calculation means for calculating a correlation matrix which indicates a correlation between received signals in each pair of the antenna elements in the receiving antenna, and calculating an eigenvalue of the correlation matrix; a ratio calculation means for calculating an eigenvalue ratio which indicates a ratio between the maximum eigenvalue in the eigenvalues calculated by the eigenvalue calculation means and a comparison eigenvalue which is an eigenvalue other than the maximum eigenvalue; and an environment judgment means for judging whether or not a current environment is, in which the radar device is located, suitable for the calibration of the radar device on the basis of the eigenvalue ratio calculated by the eigenvalue calculation means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of inspecting whether or not a current environment is, in which a radar device is installed, suitable for the calibration of the radar device, the radar device transmitting radar waves toward an object in front of the radar device, and receiving arrival radar waves which are reflected by objects, estimating at least an arrival azimuth and an object distance on the basis of information of the arrival radar waves, and generating object information which contains the arrival azimuth of the arrival radar wave and the object distance per object by which the radar wave is reflected, the arrival azimuth being an azimuth of the arrival radar waves, and the object distance being a distance between the radar device and the object, the method comprising steps of:
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calculating a correlation matrix which indicates a correlation between received signals of the arrival radar waves, and calculating an eigenvalue of the correlation matrix; calculating an eigenvalue ratio which represents a ratio between the maximum eigenvalue in the eigenvalues and a comparison eigenvalue which is an eigenvalue other than the maximum eigenvalue; and judging whether or not a current environment is, in which the radar device is located, suitable for a calibration of the radar device on the basis of the eigenvalue ratio. - View Dependent Claims (10)
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Specification