On-vehicle radar device

An on-vehicle radar device, comprising:

• frequency modulating means for modulating a frequency of a transmission signal by a triangular wave;
• transmitting means for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse to a target;
• receiving means for receiving a signal reflected by the target as a received pulse to generate a beat signal based on a frequency difference between a part of the frequency modulated transmission signal and the received pulse;
• range gate setting means for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse;
• sampling means for sampling the beat signal in each of set range gates;
• distance and relative velocity calculating means for calculating a distance to the target and a relative velocity of the target based on the sampled beat signal;
• and
• control means for controlling the frequency modulating means, the transmitting means, and the range gate setting means to change a transmission pulse width and a range gate width depending on a distance to a leading vehicle, which is acquired from the distance and relative velocity calculating means at a timing of the frequency modulation.

An on-vehicle radar device, comprising:

• frequency modulating means for modulating a frequency of a transmission signal by a triangular wave;
• transmitting means for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse to a target;
• receiving means for receiving a signal reflected by the target as a received pulse to generate a beat signal based on a frequency difference between a part of the frequency modulated transmission signal and the received pulse;
• range gate setting means for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse;
• sampling means for sampling the beat signal in each of set range gates;
• distance and relative velocity calculating means for calculating a distance to the target and a relative velocity of the target based on the sampled beat signal;
• open road determining means for determining whether or not a subject vehicle is traveling on an open road;
• and
• control means for controlling the frequency modulating means, the transmitting means, and the range gate setting means to change a transmission pulse width and a range gate width depending on a result of the determining of the open road determining means at a timing of the frequency modulation.

An on-vehicle radar device, comprising:

• frequency modulating means for modulating a frequency of a transmission signal by a triangular wave;
• transmitting means for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse to a target;
• receiving means for receiving a signal reflected by the target as a received pulse to generate a beat signal based on a frequency difference between a part of the frequency modulated transmission signal and the received pulse;
• range gate setting means for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse;
• sampling means for sampling the beat signal in each of set range gates;
• distance and relative velocity calculating means for calculating a distance to the target and a relative velocity of the target based on the sampled beat signal;
• and
• control means for controlling the frequency modulating means, the transmitting means, and the range gate setting means to change a range gate width for each range gate at a timing of the frequency modulation.

An on-vehicle radar device, comprising:

• frequency modulating means for modulating a frequency of a transmission signal by a triangular wave;
• transmitting means for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse to a target;
• receiving means for receiving a signal reflected by the target as a received pulse to generate a beat signal based on a frequency difference between a part of the frequency modulated transmission signal and the received pulse;
• range gate setting means for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse;
• sampling means for sampling the beat signal in each of set range gates;
• distance and relative velocity calculating means for calculating a distance to the target and a relative velocity of the target based on the sampled beat signal;
• and
• control means for controlling the frequency modulating means, the transmitting means, and the range gate setting means to change a range gate width depending on a travel environment and to change a frequency modulation width and modulation time at a timing of the frequency modulation.

An on-vehicle radar device, comprising:

• frequency modulating means for modulating a frequency of a transmission signal by a triangular wave;
• transmitting means for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse to a target;
• receiving means for receiving a signal reflected by the target as a received pulse to generate a beat signal based on a frequency difference between a part of the frequency modulated transmission signal and the received pulse;
• range gate setting means for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse;
• sampling means for sampling the beat signal in each of set range gates;
• distance and relative velocity calculating means for calculating a distance to the target and a relative velocity of the target based on the sampled beat signal;
• and
• control means for controlling the frequency modulating means, the transmitting means, and the range gate setting means to change a range gate width in each of range gates at a timing of the frequency modulation,
• wherein the distance and relative velocity calculating means includes measurement time changing means for changing measurement time which is time required for sampling from a start to an end of measurement data.