Driving assist device

A driving assist device for a primary vehicle, comprising:

• a receiving unit configured to receive a signal via vehicle-to-vehicle communications and/or road-to-vehicle communications using communication packets;
• an assist processing unit configured to recognize another vehicle around the primary vehicle based on information specified by the communication packets received with the receiving unit;
• a demodulation unit configured to demodulate the signal received with the receiving unit;
• a received signal strength detection unit configured to detect a received signal strength of the signal received with the receiving unit;
• a demodulation state determination unit configured to determine whether the signal received by the receiving unit is demodulated successfully;
• a communication control unit configured to determine whether a packet collision between the communication packets received with the receiving unit occurs;
• and
• a notification processing unit configured to perform an attention attracting processing to have a driver of the primary vehicle pay attention to other vehicles around the primary vehicle upon determining by the communication control unit that the packet collision occurs, wherein
• the communication control unit determines that the packet collision occurs when (i) the received signal strength detected by the received signal strength detection unit is greater than or equal to a predetermined strength threshold and (ii) the demodulation state determination unit determines that the signal is not demodulated successfully, and
• the notification processing unit is configured:
• to notify the driver that there are at least two vehicles around the primary vehicle in response to a combination of
• the communication control unit determining that the packet collision occurred and
• the assist processing unit recognizing zero or one vehicle around the primary vehicle;
• not to notify the driver that there is another vehicle around the primary vehicle in response to a combination of
• the communication control unit not determining that the packet collision occurred and
• the assist processing unit recognizing zero vehicle around the primary vehicle;
• and
• not to notify the driver that there is a first vehicle around the primary vehicle in response to a combination of
• the communication control unit not determining that the packet occurred and
• the assist processing unit recognizing a second vehicle around the primary vehicle.