Coupler system and railcar

A coupler system of a railcar, the coupler system comprising:

• a coupler main body attached to a longitudinal direction end of a carbody of the railcar so as to be rotatable in a yaw direction;
• a curvature information acquiring portion configured to acquire curvature information of a track, the railcar being located on the track;
• a speed sensor configured to measure a speed of travel of the railcar;
• a control portion configured to:
• determine a target rotation angle of the coupler main body in accordance with the acquired curvature information;
• determine whether the railcar is stopped or traveling at a predetermined coupling speed based on a speed signal from the speed sensor indicating the speed of travel of the railcar;
• and
• in response to determining that the railcar is stopped Of the railcar is traveling at the coupling speed, output a rotation signal regarding the determined target rotation angle in order to start rotating the coupler main body;
• and
• a rotation angle changing portion configured to rotate the coupler main body to the target rotation angle based on the output rotation signal.