US Patent 10570587 Periphery monitoring device of work machine

Provided is a controller (50) that includes a mechanical state acquisition section (400) that acquires information regarding a posture and an operation of a hydraulic excavator; a blind angle calculation section (500) that calculates a blind angle area from a seat in a cab (1f) of the hydraulic excavator based on the information indicating the posture and the operation of the hydraulic excavator and acquired by the mechanical state acquisition section (400); and a visibility level determination section (300) that determines a visibility level of an obstacle based on the blind angle area calculated by the blind angle calculation section (500) and a positional relationship calculated by a position relation calculation section (200). Further, a warning level determination section (600) of the controller (50) adjusts a warning level in accordance with the visibility level determined by the visibility level determination section (300).