CONTROLLER AND CONTROL METHOD FOR RIDER-ASSISTANCE SYSTEM

The invention obtains a controller and a control method capable of improving assistance performance for a rider. In a controller for a rider-assistance system, while the rider operates a drive operation section, an execution section executes first speed control operation to control a speed of a motorcycle () on the basis of positional relationship information between the motorcycle () and another vehicle () that travels in front of the motorcycle (). In the case where the presence of the necessity to stop the motorcycle () or make the motorcycle () become a crawl is determined during execution of the first speed control operation, the execution section executes second speed control operation to automatically generate deceleration to the motorcycle () and to stop the motorcycle () or make the motorcycle () become the crawl while the rider operates the drive operation section.