Cruise assist system and method

A cruise assist system for a vehicle including a steering wheel and a steering shaft coupled to the steering wheel, the cruise assist system comprising:

• a turning angle controller configured to execute an automatic cruise control task that automatically controls a turning angle of the vehicle in an automatic control mode;
• and
• a holding determiner configured to determine whether an occupant is holding the steering wheel based on the occupant's physical input to the steering shaft that is caused by the occupant's operation of the steering wheel,
• the holding determiner comprising:
• an input detector configured to detect the occupant's physical input to the steering shaft based on at least one of a first physical quantity and second physical quantities, in which the first physical quantity and the second physical quantities define rotational movement of the steering shaft,
• the first physical quantity comprising the occupant's physical input and a disturbance input to the steering shaft, the disturbance input being different from the occupant's physical input, and
• the second physical quantities having a relationship therebetween, the relationship changing in response to rotational movement of the steering shaft caused by the occupant's physical input, wherein
• when detecting the occupant's physical input to the steering shaft based on the first physical quantity, the input detector is configured to detect the occupant's physical input by removing the disturbance input from the first physical quantity,
• when detecting the occupant's physical input to the steering shaft based on the second physical quantities, the input detector is configured to detect the occupant's physical input based on the relationship between the second physical quantities,
• the holding determiner further comprises, when the first physical quantity is used by the input detector, a determiner configured to:
• perform a comparison of the occupant's physical input with a predetermined threshold;
• and
• determine whether the occupant is holding the steering wheel in accordance with a result of the comparison, and
• a value of the predetermined threshold during execution of the automatic cruise control task being set to be larger than a value of the predetermined threshold during no execution of the automatic cruise control task.