A patrol robot conducts electricity check-up at a transformer substation in Qingpu District of east China's Shanghai, Oct.18, 2018. Patrol robots have been deployed to ensure power supply for the first China International Import Expo in November. (Xinhua/Ding Ting)

A patrol robot conducts electricity check-up at a transformer substation in Qingpu District of east China's Shanghai, Oct.18, 2018. Patrol robots have been deployed to ensure power supply for the first China International Import Expo in November. (Xinhua/Ding Ting)

A patrol robot conducts electricity check-up at a transformer substation in Qingpu District of east China's Shanghai, Oct.18, 2018. Patrol robots have been deployed to ensure power supply for the first China International Import Expo in November. (Xinhua/Ding Ting)