Roadside device, communication system, and danger detection method

A communication system including a terminal device configured to be carded by a moving object and a roadside device disposed on or near a road,

• wherein the terminal device comprises;
• a state detector configured to detect a state of the moving object;
• a first communication device configured to perform Intelligent Transport System (ITS) communication;
• and
• a first controller that, when detecting a risky action of the moving object based on a detection result of the state detector, transmits a message including state information indicating that the moving object is in a risky state from the first communication device,
• wherein the roadside device comprises:
• an object detector configured to detect moving objects on roads;
• a second communication device configured to perform Intelligent Transport System (ITS) communication;
• and
• a second controller that, when the message including the state information is received by the second communication device from the terminal device, acquires position information of another moving object present around the moving object in the risky state based on a detection result of the object detector, and determines a risk of collision between the moving objects based on the position information of the other moving object, and
• wherein the second controller is configured to control a detection area of the object detector based on position information of the terminal device included in the message received by the second communication device such that a predetermined area around the moving object in the risky state is contained in the detection area.

A risk detection method for detecting, in a roadside device disposed on or near a road, a risk of collision between moving objects present around the roadside device, the method comprising:

• when a message including state information indicating that a moving object is in a risky state is received from a terminal device carried by the moving object, acquiring position information of another moving object present around the moving object in the risky state based on a result of detecting moving objects on roads by object detection;
• determining a risk of collision between the moving objects based on the position information of the other moving object;
• and
• controlling a detection area of the object detection based on position information of the terminal device included in the message received from the terminal device such that a predetermined area around the moving object in the risky state is contained in the detection area.