Fujitsu Ten Limited

Fujitsu Corporation

Yasuhiro Sekiguchi

Masayuki Kishida

Tokio Shinagawa

Masaki Hiromori

Daisaku Ono

Sadanori Matsui

Masaki Hirōmōri

An accurate intermittent triangular wave signal without waveform distortion is generated by a triangular wave generation circuitincluding a rectangular wave generation circuitfor generating an intermittent rectangular wave signal in which a rectangular wave interval and a direct current interval of a predetermined level are repeated; an integration circuitfor generating an intermittent triangular wave signal in which a triangular wave interval and a direct current interval are repeated based on a reference signal and the intermittent rectangular wave signal generated by the rectangular wave generation circuit; and a triangular wave correcting circuitfor correcting waveform distortion of the intermittent triangular wave signal based on a differential voltage between a starting point and an ending point of the direct current interval of the intermittent triangular wave signal output from the integration circuit

Triangular wave generation circuit

When a new target is detected, if it is determined that the distance difference between the newly detected target and the previously detected target is within a predetermined range, the difference between the relative velocity of the newly detected target and the relative velocity of the previously detected target is obtained to determine whether the difference is greater than a predetermined value &Dgr;V , and when the difference is greater than the predetermined value, it is determined that the new target is a target obtained as a result of mispairing. Further, when the difference between the relative velocity of the newly detected target and the relative velocity of the previously detected target is greater than the predetermined value &Dgr;V , then the difference between a distance derivative of the newly detected target over a prescribe time and the relative velocity of the previously detected target is obtained, and when the difference is greater than a predetermined value &Dgr;V which is smaller than the predetermined value &Dgr;V , it is determined that the new target is a target obtained as a result of mispairing.

Mispairing determination and signal processing method for FM-CW radar

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. When there are two targets substantially equal in distance and velocity, the target located outward, as viewed from the radar-equipped vehicle, is excluded from the output data by determining it as being a ghost occurring due to reflections from a wall or like structure. After checking continuity, if the present data is not one calculated by extrapolation but the previous data is one calculated by extrapolation, filtering calculations are not performed for the calculation of the relative velocity; in other cases, the filtering calculations are performed.

Radar data processing apparatus and data processing method

Growing community of inventors

Kobe, Japan

Yasuhiro Sekiguchi