Air quality-monitoring robot patrols at Zhengzhou railway station

A robot patrols at the Zhengzhou East Railway Station in Zhengzhou, capital of Central China's Henan province, Feb 15, 2017. A patrol robot is set at Zhengzhou East Railway Station recently, which can monitor air quality, temperature and humidity all day long, discover fire emergency and also help keep clear of the station at night.[Photo/Xinhua]