ULTRASONIC PRESENCE DETECTION SYSTEM AND METHOD FOR BUILDING MACHINE

Apparatus for sensing an operator in an operator space of a machine, comprising: an ultrasonic sensor positioned relative to an operator space and arranged to detect a presence of an operator within an operator occupancy region of the operator space, said operator occupancy region being spaced apart from the ultrasonic sensor by at least a first predetermined distance and extending up to a second predetermined distance from the sensor; wherein, the sensor is arranged to generate a control signal for deactivating operator controls of the machine responsive to the detection of an absence of the operator in the operator occupancy region.