Specialized category for proximity detection sensors mounted on industrial robots and automation equipment. Handles various sensors that detect object approach or presence without contact, including photoelectric sensors, ultrasonic sensors, capacitive sensors, and inductive sensors. Used for robot arm positioning, workpiece detection, collision avoidance, and safety monitoring applications, where detection distance, response speed, and detection accuracy are key selection criteria. Clearly distinguished from contact-type limit switches and image processing inspection equipment, comprehensively covering sensors specialized for short-range object detection.