US 7,612,707 B2 · Configurable radar sensor

Abstract

Multiple signal characteristics representing an entire field of view of an FMCW (FM-CW) sensor are evaluated to determine whether the field of view has changed. Signal characteristics representing the field can be compared to representative signal characteristics obtained from previous scans. At least one signal characteristic representing at least a portion of the scene can be evaluated by comparing the signal characteristic to a dynamic threshold. The dynamic threshold can be redefined after each scan from the statistics of the signal characteristic. The dead zone of a sensor can be reduced by filtering out noise that would otherwise overshadow a signal representing the near-field region of a scene. The noise can be filtered by subtracting a polynomial curve from a time-domain signal representing the scene after fitting the polynomial curve to a representative signal generated based on previous scene scans.

Claims23

Dependent claims

A detection system comprising:

a sensor including a receiver for obtaining over a predetermined period of time a plurality of scene signals representing a scene viewed by the sensor;
a memory communicatively coupled to the sensor, the memory configured to store a predetermined number of the scene signals;
and
a signal processor communicatively coupled to at least one selected from the group consisting of the sensor and the memory, the signal processor including:
a signal characteristics module configured to determine a plurality of signal characteristics for each scene signal stored in the memory, each signal characteristic defining an aspect of the respective scene signal;
a compilation module configured to determine a representative value of each signal characteristic based on the signal characteristics of the scene signals stored in the memory;
and
an assessment module configured to obtain a first scene signal from the sensor and to compare each of a plurality of signal characteristics of the first scene signal to the representative value of the respective signal characteristic to determine whether each signal characteristic has changed.

5 more elements

A dynamic detector system comprising:

a radar sensor configured to scan a scene to obtain a first FMCW detection signal;
a signal processor communicatively coupled to the radar sensor, the signal processor being configured to obtain at least one signal characteristic of the first FMCW detection signal, the signal processor also being configured to compare each signal characteristic of the first FMCW detection signal to at least one dynamic threshold of the signal characteristic to ascertain changes in the scene;
and
a threshold processor communicatively coupled to the signal processor, the threshold processor being configured to define the at least one dynamic threshold for each signal characteristic based on corresponding signal characteristics of a plurality of previously obtained FMCW detection signals, the threshold processor also being configured to redefine the at least one dynamic threshold of each signal characteristic after obtaining a subsequent FMCW detection signal based on the signal characteristics of the first FMCW detection signal and on the signal characteristics of the previously obtained FMCW detection signals.

1 more element

A signal processing system for shortening a dead zone of a sensor that scans a scene to obtain at least a first detection signal, the signal processing system comprising:

a memory configured to store at least one signal characteristic for each of a plurality of detection signals previously obtained from the sensor, wherein objects to be detected were absent from at least a near-field region of the scene when the detection signals were obtained;
and
a signal processor communicatively coupled to the memory, the signal processor including:
a compilation module configured to determine a representative signal based on the detection signals that have signal characteristics stored in the memory;
a generation module configured to fit a polynomial curve to the representative signal when the representative signal is configured in a time domain;
a subtraction module configured to subtract the polynomial curve from the first detection signal obtained by the sensor when the first detection signal is configured in the time domain to obtain a filtered detection signal;
and
an evaluation module configured to compare at least one signal characteristic of the filtered detection signal to a corresponding threshold of the signal characteristic to ascertain changes in the scene when the filtered detection signal is configured in a frequency domain;
whereby noise that would otherwise overshadow a signal representing the near-field region of the scene is filtered from the first detection signal before the evaluating the first detection signal to ascertain changes in the scene, thereby shortening the dead zone of the sensor.

6 more elements

Dependencies are inferred from the claim text.

Configurable radar sensor

Life of this patent

Configurable radar sensor

Life of this patent

Abstract

Claims23