US 5,302,956 AGranted

Multi-frequency, multi-target vehicular radar system using digital signal processing

AssigneeVorad Safety Systems, Inc.

InventorsJimmie R. Asbury, Bryan D. Woll, Van R. Malan

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Abstract

A vehicular collision avoidance radar system using digital signal processing techniques including a transmit section that generates a two channel transmit frequency. An antenna both transmits the transmit signal and receives a reflected receive signal. A Schottky diode mixer generates a difference signal having a frequency equal to the transmit frequency minus the receive frequency. A signal switch in a front end electronics section time demultiplexes and samples the channel 1 and channel 2 signals. The samples are coupled to a two-channel analog to digital (A/D) converter. A digital electronics section receives the digital information and performs a Fast Fourier Transform (FFT) on each channel of digital data to determine relative speed and range of a target based upon the frequency and the difference in phase of the two channels. The digital electronics section also receives information regarding the status of vehicle operation and/or controls to determine the degree of danger presented by an identified target.

Claims14

Dependent claims

A vehicular radar system for detecting targets about an automotive vehicle having an operator, and warning the operator of dangers presented by the targets, including:

a) a microwave transceiver means for transmitting, receiving, and comparing the frequencies of at least two radio frequency (RF) signals, and generating a time-multiplexed output signal of the frequencies;
b) front end electronics means, coupled to the microwave transceiver means, for digitizing the time-multiplexed output signal generated by the microwave transceiver means and converting the output signal of the microwave transceiver means from an analog signal to an interleaved sequence of digital data words, each subsequence of digital data words corresponding to one of the frequencies;
c) digital electronics means for determining the presence of targets, calculating the range of each target, and calculating the relative speed of each target with respect to the automotive vehicle, including:
(1) at least one digital signal processor means, coupled to the front end electronics means, for mapping the digital data words output by the front end electronics means from the time domain to the frequency domain for each subsequence of digital data words to determine the frequency of the received signal from each target;
(2) at least one microcontroller means, coupled to at least one of the digital signal processor means, for determining the range of each target from the phase difference between the received signal from such target for each of the RF signals, and for determining the relative speed from the frequency difference between the received signal from such target for each of the RF signals and for tracking the targets and assessing dangers presented by the targets as a function of such determined range and relative speed;
and
d) display and sensor means coupled to the microcontroller means for presenting a indications to the automotive vehicle operator of the presence of danger presented by the targets.

4 more elements

A vehicular radar system for detecting targets about an automotive vehicle having an operator, sensing the status of the controls and relevant environmental conditions in which the automotive vehicle is operating, and warning the operator of the automotive vehicle of dangers presented by the targets, including:

a) a dual-channel microwave transceiver means for transmitting, receiving, and comparing the frequency of radio frequency signals, including:
(1) an antenna means for transmitting a radio frequency transmit signal, and for receiving a radio frequency receive signal reflected off a target in the environment of the automotive vehicle;
and
(2) a frequency difference detection means coupled to the antenna means for generating an output signal having a frequency equal to the difference between the frequency of the radio frequency transmit signal and the frequency of the radio frequency received signal;
b) a dual-channel front end electronics means coupled to the frequency difference detection means for digitizing the output signal generated by the difference detection means, including an analog to digital converter means coupled to the frequency difference detection means for converting the output of the difference detection means from an analog signal to a serial stream of digital data words;
c) a digital electronics means for determining the presence of targets, calculating the range of each target, and calculating the relative speed of each target with respect to the automotive vehicle, including:
(1) a digital signal processor means coupled to the analog to digital converter means for mapping the digital output of the analog to digital converter means from the time domain to the frequency domain to determine range and relative speed of the targets from which the radio frequency receive signal is reflected;
(2) a microcontroller means coupled to the digital signal processor means for tracking the targets, and assessing dangers presented by the targets;
and
d) a display and sensor means coupled to the microcontroller means for presenting a indications to the automotive vehicle operator of the presence of the danger presented by the targets, and sensing the status of the controls and relevant environmental conditions in which the automotive vehicle is operating, including:
(1) a plurality of sensor means for determining the status of the vehicle controls;
(2) a warning means for indicating to the operator of the vehicle that danger is present;
and
(3) a monitor means for communicating the status of the vehicular radar system to external devices.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/930,066Filed 14 Aug 1992
Granted: 12 Apr 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

G01S 7/023
Of systems according to group G01S13/00: interference mitigation, e.g. reducing or avoiding non-intentional interference with other…
G01S 7/0232
Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile…:…
G01S 13/325
Using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated: using transmission of coded signals,…
G01S 13/584
Using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting…:…