FMCW radar system
AssigneeDenso Corporation
InventorsYukimasa Tamatsu, Hiroaki Kumon
Life of this patent
Estimating the term…
Abstract
An inventive frequency modulated continuous wave (FMCW) radar system realizes both of a quick detection of higher relative speed provisional target and a sure detection of smaller relative speed provisional target. The number of detection cycles used for a paring validity check (a test to see if a detected target or a pair of frequencies is an actual target or a pair for an actual target) is set in response to the relative velocity. This enables the target information for a target of higher relative velocity to be output the more quickly
Claims10
A frequency modulated continuous wave (FMCW) radar system for detecting the distance and the velocity of a target relative to the radar system every detection cycle, the radar system including:
- a transmitter including:
- means for generating a transmission signal the frequency of which increases during an increasing section of a duration and decreases during an decreasing section of said duration;
- a receiver including:
- means for extracting a beat component signal from said transmission signal and a received return signal reflected by said target;
- and
- processing means including:
- (a) means for extracting peak frequencies at which an amplitude of said beat component signal becomes a peak from said beat component signals (peak frequencies extracted during said increasing section being referred to as “increasing section peak frequencies” and peak frequencies extracted during said decreasing section being referred to as “decreasing section peak frequencies”);
- (b) means for finding target information which includes a distance and a velocity of each of said definitely detected targets from a pair of increasing and decreasing section peak frequencies selected for said definitely detected target from said extracted peak frequencies (said pair being referred to as “peak pair”);
- (c) means for making provisional peak pairs from extracted peak frequencies other than those used for peak pairs associated with said definitely detected targets, assuming that said provisional peak pairs correspond to respective provisional targets;
- (d) means, activated every detection cycle, for making a test to see if each of continuation provisional targets which have been detected at least one detection cycle ago has continuity with any of said provisional peak pairs;
- (e) means for registering a continuation provisional target that have passed said tests made in a preset number of detection cycles to be a new definitely detected target;
- (f) means for registering a provisional target that has judged to be in lack in continuity with any of said continuation provisional targets as a new continuation provisional target;
- and
- (g) means for setting said preset number associated with said new continuation provisional target to a value, said value being such that the higher the relative velocity of said new continuation provisional target, the smaller said value and vice versa.
A computer program to be executed in a FMCW radar system for detecting the distance and the velocity of a target relative to the radar system every detection cycle, wherein the radar system includes a transmitter for transmitting a transmission signal the frequency of which increases during an increasing section of a duration and decreases during an decreasing section of said duration;
- a receiver including means for extracting a beat component signal from said transmission signal and a received return signal reflected by said target;
- and a processing portion including means for extracting peak frequencies at which an amplitude of said beat component signal becomes a peak from said beat component signal, (peak frequencies extracted during said increasing section being referred to as “increasing section peak frequencies” and peak frequencies extracted during said decreasing section being referred to as “decreasing section peak frequencies”), the computer program including the steps of:
- (a) finding target information which includes a distance and a velocity of each of said definitely detected targets from a pair of increasing and decreasing section peak frequencies selected for said definitely detected target from said extracted peak frequencies (said pair being referred to as “peak pair”);
- (b) making provisional peak pairs from extracted peak frequencies other than those used for peak pairs associated with said definitely detected targets, assuming that said provisional peak pairs correspond to respective provisional targets;
- (c) every detection cycle, making a test to see if each of continuation provisional targets which have been detected at least one detection cycle ago has continuity with any of said provisional peak pairs;
- (d) registering a continuation provisional target that have passed said tests made in a preset number of detection cycles to be a new definitely detected target;
- (e) registering a provisional target that has judged to be in lack in continuity with any of said continuation provisional targets as a new continuation provisional target;
- and
- (f) setting said preset number associated with said new continuation provisional target to a value, said value being such that the higher the relative velocity of said new continuation provisional target, the smaller said value and vice versa.
Dependencies are inferred from the claim text.