Traffic light passing support system, in-vehicle apparatus for the same, and method for the same

An in-vehicle apparatus for a traffic light passing support system for supporting a vehicle to pass a traffic light, the traffic light passing support system including a traffic light, which includes a signal light and a traffic-light control unit for controlling the signal light, the in-vehicle apparatus comprising:

• a first acquisition unit configured to successively obtain vehicle speed information on a speed of the vehicle;
• a second acquisition unit configured to successively obtain present position information of the vehicle;
• a third acquisition unit configured to successively obtain traffic light information including a location of the traffic light, a lighting cycle, and a transition time before a color of the traffic light is changed to a subsequent color;
• a first arithmetic unit configured to calculate an at-constant-speed required time, which is needed for the vehicle to arrive at the traffic light when the vehicle maintains a vehicle speed, according to the vehicle speed information, the present position information, and the traffic light information;
• a determination unit configured to determine whether the vehicle can pass the traffic light by maintaining the vehicle speed, according to the at-constant-speed required time and the traffic light information;
• a request generating unit configured to, in response to a determination of the determination unit that the vehicle cannot pass the traffic light, generate a first request signal to request the traffic light to control the signal light so as to light a passing permission color after the at-constant-speed required time elapses;
• an in-vehicle transmission unit configured to transmit the first request signal to the traffic light;
• and
• a control unit configured to:
• cause the traffic light to determine whether the traffic light is capable of controlling the signal light according to the first request signal transmitted from the in-vehicle transmission unit and according to whether there is another control request of a signal light from an other in-vehicle apparatus of another vehicle, and
• transmit a determination result to the in-vehicle apparatus;
• wherein the in-vehicle apparatus further in a second arithmetic unit configured to, in response to a determination result not to accept the first request signal, calculate an in-deceleration required time, which is needed for the vehicle to arrive at the traffic light when a driver of the vehicle does not perform both braking and acceleration, according to the vehicle speed information, the present position information, the traffic light information, and a deceleration quantity when the driver does not perform both braking and acceleration,
• wherein the determination unit is further configured to determine whether the vehicle can pass the traffic light when decelerating by the deceleration quantity, according to the in-deceleration required time and the traffic light information,
• wherein the request generating unit is further configured to, in response to a determination of the determination unit that the vehicle cannot pass the traffic light when decelerating by the deceleration quantity, generate the second request signal to request the traffic light to control the signal light to light a passing permission color after the in-deceleration required time elapses,
• wherein the in-vehicle transmission unit is further configured to transmit the second request signal to the traffic light, and
• wherein the control unit is further configured to cause the traffic light to control the signal light according to the second request signal when the traffic light receives the second request signal.

A method for supporting a vehicle to pass a traffic light, the method comprising:

• successively obtaining vehicle speed information on a speed of the vehicle by an in-vehicle apparatus;
• successively obtaining present position information on a present position of the vehicle by the in-vehicle apparatus;
• successively obtaining traffic light information including a location of the traffic light, a lighting cycle of the traffic light, and a transition time by the in-vehicle apparatus, the transition time being a time before a color of the traffic light is changed to a subsequent color;
• calculating an at-constant-speed required time by the in-vehicle apparatus according to the obtained vehicle speed information, the obtained present position information, and the obtained traffic light information, the at-constant-speed required time being a time needed for the vehicle to arrive at the traffic light when the vehicle maintains a vehicle speed;
• determining by the in-vehicle apparatus whether the vehicle can pass the traffic light when maintaining the vehicle speed according to the calculated at-constant-speed required time and the obtained traffic light information;
• generating a first request signal by the in-vehicle apparatus, in response to a determination that the vehicle cannot pass the traffic light, to request the traffic light to control a signal light so as to light a passing permission color after the at-constant-speed required time elapses;
• transmitting the first request signal from the in-vehicle apparatus to the traffic light;
• receiving the transmitted first request signal by the traffic light;
• controlling the signal light by the traffic light according to the received first request signal;
• determining by the traffic light whether the traffic light is capable of controlling the signal light according to the received first request signal and according to whether there is another control request of a signal light from another in-vehicle apparatus of another vehicle and transmitting a determination result to the in-vehicle apparatus;
• calculating by the in-vehicle apparatus, in response to a determination result not to accept the first request signal, an in-deceleration required time, which is needed for the vehicle to arrive at the traffic light when a driver of the vehicle does not perform both braking and acceleration, according to the vehicle speed information, the present position information, the traffic light information, and a deceleration quantity when the driver does not perform both braking and acceleration;
• determining by the in-vehicle apparatus whether the vehicle can pass the traffic light when decelerating by the deceleration quantity, according to the in-deceleration required time and the traffic light information;
• generating by the in-vehicle apparatus, in response to a determination that the vehicle cannot pass the traffic light when decelerating by the deceleration quantity, a second request signal to request the traffic light to control the signal light to light a passing permission color after the in-deceleration required time elapses;
• transmitting the second request signal to the traffic light;
• and
• controlling by the traffic light the signal light according to the second request signal when the traffic-light receiving unit receives the second request signal.