CONTROLLER AND CONTROL METHOD

The present invention obtains a controller and a control method capable of hastening identification of an object or an event to be focused by a rider of a straddle-type vehicle, the rider having perceived haptic motion. A controller () for a rider-assistance system () mounted to a straddle-type vehicle () includes: a determination section that determines necessity of a warning given to the rider; and a haptic motion performing section that performs haptic motion at least once to reduce or increase acceleration/deceleration of the straddle-type vehicle () only for a moment. The haptic motion performing section changes a priority of each wheel () at the time of changing a braking force to reduce or increase the acceleration/deceleration only for the moment in the haptic motion according to a focusing direction that is a direction in which the rider should focus by the warning.