CONTROLLER FOR RIDER-ASSISTANCE SYSTEM, RIDER-ASSISTANCE SYSTEM, AND CONTROL METHOD FOR RIDER-ASSISTANCE SYSTEM

The present invention obtains a controller capable of improving assistance performance of a rider. The present invention also obtains a rider-assistance system including such a controller. The present invention further obtains a control method for such a rider-assistance system. In the case where travel posture information of a lean vehicle () is acquired and the travel posture information is information indicating that leaning of the lean vehicle () exceeds a reference, initiation of first rider-assistance operation for assisting with driving by a rider by using information on a first target (T) located on a side of a travel line (DL) of the lean vehicle () is prohibited, and initiation of second rider-assistance operation for assisting with driving by the rider using information on a second target (T) located on the travel line (DL) of the lean vehicle () is permitted.