Beijing, March 7 (Youth.cn) - The 20th Tianjin International Industrial Expo started on March 6th. Visitors were getting to know about the intelligent optical tracking 3D scanning robot at the robot and automation exhibition area. Nearly 1000 brands joined the Expo with over 4000 intelligent and digital exhibits on show. Exhibitors are mainly from industries like numerical control machine, robots, industrial automation, welding machine and laser cutting, new energy equipment and car equipment. Photo/VCG