On-vehicle control device, traveling speed control method, and computer program

A method of controlling a traveling speed of a vehicle, which is executed by an on-vehicle control device that controls the traveling speed of the vehicle, the method comprising:

• acquiring a present light color of a traffic light unit installed at an intersection, from a communication device outside the vehicle or a sensor mounted on the vehicle;
• calculating an avoidance position and an avoidance speed with respect to a dilemma zone at a time when yellow light starts, by using a yellow interval of the traffic light unit, a deceleration of the vehicle, and a system delay time of the vehicle;
• and
• executing a first deceleration process of reducing the traveling speed of the vehicle at the avoidance position to a speed equal to or lower than the avoidance speed, in a case where a present position of the vehicle is on an upstream side relative to the avoidance position, the present light color is green, and a distance from the intersection to the present position of the vehicle is larger than a distance from the intersection to the avoidance position, wherein
• the avoidance position and the avoidance speed are calculated from coordinates of an intersection of a straight line Ls and a curve Lc defined by the following:
• Ls=Y×V
• Lc=τ×V+(½d)×V2,
• where τ is the system delay time of the vehicle, V is the traveling speed of the vehicle, d is the deceleration of the vehicle, and Y is the yellow interval of the traffic light unit.

A non-transitory computer readable storage medium storing a computer program configured to cause a computer to function as an on-vehicle control device that controls a traveling speed of a vehicle including the on-vehicle control device, the computer program causing the computer to function as:

• an acquisition unit configured to acquire a present light color of a traffic light unit installed at an intersection, from a communication device outside the vehicle or a sensor mounted on the vehicle;
• a calculation unit configured to calculate an avoidance position and an avoidance speed with respect to a dilemma zone at a time when yellow light starts, by using a yellow interval of the traffic light unit, a deceleration of the vehicle, and a system delay time of the vehicle;
• and
• a control unit configured to execute a first deceleration process of reducing the traveling speed of the vehicle at the avoidance position to a speed equal to or lower than the avoidance speed, in a case where a present position of the vehicle is on an upstream side relative to the avoidance position, the present light color is green, and a distance from the intersection to the present position of the vehicle is larger than a distance from the intersection to the avoidance position, wherein
• the avoidance position and the avoidance speed are calculated from coordinates of an intersection of a straight line Ls and a curve Lc defined by the following:
• Ls=Y×V
• Lc=τ×V+(½d)×V2,
• where τ is the system delay time of the vehicle, V is the traveling speed of the vehicle, d is the deceleration of the vehicle, and Y is the yellow interval of the traffic light unit.