Multi-frequency automatic radar system

Claim 2

A vehicle radar system comprising: (a) means for successively transmitting a radar signal at a plurality of different frequencies, and operative to continuously transmit the radar signal through a succession of transmit time frames, each of which comprises at least (1) a first portion during which the radar signal is transmitted at a reference frequency, and (2) a second portion during which the radar signal is transmitted at a frequency different from the reference frequency, each such portion being further divided into a plurality of transmit time interval windows; (b) means for receiving the transmitted radar signals at the plurality of different frequencies as reflected back to the radar system by a target, and operative to receive the reflected radar signals during receive time interval windows, each such receive time interval window corresponding to a transmit time interval window of the transmit time frames of the means for successively transmitting; (c) means, coupled to the means for receiving, responsive to the rate of phase shift in a received signal received during a selected one of the receive time interval windows, for determining opening or closing rate of the target reflecting back the radar signals; (d) means, coupled to the means for receiving, responsive to phase shift differences between signals received during a first selected time interval window associated with a first transmit frequency and a second selected time interval window associated with a second transmit frequency, for determining range of the target reflecting back the radar signals; and (d) means, coupled to the means for receiving and the means for successively transmitting, for identifying transmit and receive time interval windows which are not utilized in connection with receipt of transmitted radar signals; whereby each receive time interval window which is not utilized in connection with receipt of transmitted radar signals is available to perform functions other than determining opening or closing rate of the target reflecting back the radar signals, and determining range of the target reflecting back the radar signals.

Claim 3

The invention set forth in claim 1, wherein the means for successively transmitting is operative to continuously transmit a radar signal through a succession of time frames, each of which comprises (1) a first portion during which the radar signal is transmitted at a reference frequency, (2) a second portion during which the radar signal is transmitted at a first frequency above the reference frequency, and (3) a third portion during which the radar signal is transmitted at a second frequency below the reference frequency.

Claim 4

The invention set forth in claim 1, wherein each time interval window may vary from approximately 2 μs to approximately 4.5 μs in duration.

Claim 5

A vehicle radar system comprising the combination of: a. means for successively transmitting radar signals at three different frequencies, through a succession of time frames, each such time frame comprising a transmit frequency interval during which a corresponding one of the three different frequencies is transmitted, each such transmit frequency interval being divided into a plurality of transmit time interval windows; b. means for receiving the transmitted radar signals at the three different frequencies as reflected back to the radar system by a target, the received signal comprising receive frequency intervals, each corresponding to a unique transmit frequency interval, and being divided into a plurality of receive time interval windows, each such receive time interval window corresponding to a unique one of the transmit time interval windows; c. means for separating the received radar signals into three different signal paths according to the three different frequencies thereof, such that each signal path is associated with particular receive time interval windows; d. means responsive to the rate of phase shift of signals in a first one of the three different signal paths during a predetermined receive time interval window associated with the first signal path for determining closing rate of the target reflecting back the radar signals; e. means responsive to phase shift differences between signals in the second and third ones of the three different signal paths during a predetermined receive time interval window associated with the second signal path and a predetermined time interval window associated with the third signal path for determining range of the target reflecting back the radar signals; and f. means, coupled to the means for receiving and the means for successively transmitting, for identifying transmit and receive time interval windows which are not utilized in connection with receipt of transmitted radar signals; whereby each receive time interval window which is not utilized in connection with receipt of transmitted radar signals is available to perform functions other than determining closing rate of the target reflecting back the radar signals, and determining range of the target reflecting back the radar signals.

Claim 6

A vehicle radar system comprising the combination of: a. means for successively transmitting radar signals at three different frequencies, through a succession of time frames, each such time frame comprising a transmit frequency interval during which a corresponding one of the three different frequencies is transmitted, each such transmit frequency interval being divided into a plurality of transmit time interval windows; b. means for receiving the transmitted radar signals at the three different frequencies as reflected back to the radar system by a target, the received signal comprising receive frequency intervals, each corresponding to a unique transmit frequency interval, and being divided into a plurality of receive time interval windows, each such receive time interval window corresponding to a unique one of the transmit time interval windows; c. means for separating the received radar signals into three different signal paths according to the three different frequencies thereof, such that each signal path is associated with particular receive time interval windows; d. means responsive to the rate of phase shift of signals in a first one of the three different signal paths during a predetermined receive time interval window associated with the first signal path for determining closing rate of the target reflecting back the radar signals; e. means responsive to phase shift differences between signals in the second and third ones of the three different signal paths during a predetermined receive time interval window associated with the second signal path and a predetermined time interval window associated with the third signal path for determining range of the target reflecting back the radar signals; and f. means, coupled to the means for receiving and the means for successively transmitting, for identifying transmit and receive time interval windows which are not utilized in connection with receipt of transmitted radar signals; whereby each receive time interval window which is not utilized in connection with receipt of transmitted radar signals is available to perform functions other than determining closing rate of the target reflecting back the radar signals, and determining range of the target reflecting back the radar signals.

Claim 7

The invention as set forth in claim 4, wherein a first of the three different frequencies is below a reference frequency, a second of the three different frequencies is above the reference frequency, and a third of the three different frequencies is at the reference frequency.

Claim 8

A vehicle radar system comprising the combination of: a. a transmitter for continuously transmitting a radar signal at a succession of different frequencies and including a timing generator for providing timing signals defining intervals for the different frequencies and defining a plurality of transmit time interval windows within each frequency interval, a modulator responsive to the timing signals for providing signals denoting desired frequencies, and a transmitter output for transmitting radar signals at frequencies determined by the signals from the modulator; and b. a receiver for receiving the transmitted radar signals reflected back to the radar system by a target, and including a plurality of signal paths, a plurality of processing devices coupled to the plurality of signal paths, and a demodulator responsive to the timing signals provided by the timing generator for routing received radar signals to selected ones of the processing devices during a first set of predetermined time interval windows to determine range and closing and opening rate, and routing received radar signals to selected other processing devices during a second set of predetermined time interval windows to perform functions unrelated to determining range and rate of closing and opening.

Claim 9

A vehicle radar system comprising the combination of: a. a transmitter for continuously transmitting a radar signal at a succession of different frequencies and including a timing generator for providing timing signals defining intervals for the different frequencies and defining a plurality of transmit time interval windows within each frequency interval, a modulator responsive to the timing signals for providing signals denoting desired frequencies, and a transmitter output for transmitting radar signals at frequencies determined by the signals from the modulator; and b. a receiver for receiving the transmitted radar signals reflected back to the radar system by a target, and including a plurality of signal paths, a plurality of processing devices coupled to the plurality of signal paths, and a demodulator responsive to the timing signals provided by the timing generator for routing received radar signals to selected ones of the processing devices during a first set of predetermined time interval windows to determine range and closing and opening rate, and routing received radar signals to selected other processing devices during a second set of predetermined time interval windows to perform functions unrelated to determining range and rate of closing and opening.

Claim 10

The invention set forth in claim 4, wherein the modulator comprises a voltage regulator and a plurality of frequency control switches coupled to the voltage regulator and operative to provide voltages denoting desired frequencies to the transmitter in response to timing signals from the ring counter logic circuit.

Claim 11

The invention set forth in claim 4, wherein the demodulator comprises a plurality of analog switches, each being coupled to a different one of the plurality of different signal paths and to receive the received radar signals, the plurality of analog switches being operative to route the received radar signals to different ones of the plurality of different signal paths in response to timing signals from the ring counter logic circuit.

Claim 12

The invention set forth in claim 4, wherein the receiver further includes a signal processor means coupled to the plurality of signal paths, and responsive to the rate of phase shift in a received reflected signal corresponding to one of the succession of different frequencies, for determining opening or closing rate of the target reflecting back the radar signals, and responsive to phase shift differences between received reflected signals corresponding to two different ones of the succession of different frequencies, for determining range of the target reflecting back the radar signals.

Claim 13

The invention set forth in claim 9, wherein the signal processor means is analog.

Claim 14

The invention set forth in claim 9, wherein the signal processor means is digital.

Claim 15

The invention set forth in claim 6, wherein the radar signal receiver includes a data processor responsive to the range and the closing rate of the target reflecting back the radar signals for determining a hazard level of the target in accordance with an algorithm.