Technical features: First, non-intrusive, no modification to elevator hardware or control system, plug and play; Second, AI recognition, vision recognition of elevator status, door switch and floor display; Third, wireless interaction, Bluetooth/Wi-Fi communication with elevator control, call, floor selection and feedback; Fourth, multi-machine collaboration, multiple robots queue, avoid and schedule to avoid congestion; Fifth, scene coverage, office buildings, shopping malls, hospitals and communities, full adaptation for delivery, security, inspection and cleaning.