**The First Person in Welding Robot Programming: Liu Jianshu**
In the EMU bogie welding workshop, the sound of electric welding is accompanied by the smooth movement of robotic arms, creating a scene that feels like something out of a sci-fi movie. Liu Jianshu moves between the robots, observing the welding of crossheads and side beams on the moving car bogies. Over 30 robots are the main players here, but the real mastermind behind them is Liu Jianshu. He writes all the programs that guide the robots through complex welding tasks.
Since joining the company in 1999, Liu has worked on the front lines of production. “At first, I used to do manual welding,†he recalls. “That was the foundation of the welding job. Then I moved into welding robot programming. I found it very interesting and suitable for my personality.†For 17 years, he has remained in this position, one of the few from his original group of workers who stayed.
Unlike traditional hand-held welding torches, operating a welding robot requires precise programming. “To complete a complex welding process without a torch, you have to work harder to get the quality in exchange for technology,†Liu explains. The “remote control†he uses is actually a teaching device—a small computer connected to the robot’s internal software. It allows him to program and operate the robot efficiently.
In the absence of technical documents, Liu taught himself and developed nearly 200 automated welding procedures for over 30 types of large parts. These solutions tackled problems that even international experts struggled with. His work earned him the title of “First Person in Welding Robot Programming.†In 2015 and 2017, he was appointed as a skill expert at CRRC Sifang Co., Ltd. and a Chinese Chongjie skill expert.
**Controlling Welding Robots to Boost Efficiency by Four Times**
“The programming of a welding robot involves guiding it through each step, collecting data, and optimizing the program so the robot can work independently,†Liu explains. At each welding point, he inputs the required angle, parameters, and trajectory. Once corrected, the robot can remember and repeat the process perfectly.
After each programming session, he conducts small batch tests to optimize the program. Initially, he had to test more than ten pieces, but now just one or two are enough. Liu breaks down the entire welding process into thousands of points, each containing a large amount of data. On an EMU bogie, there are over 7,000 such points. Programming is like teaching the robot to perform a task once, and then it remembers it forever.
His groundbreaking “multi-layer multi-channel split-layer one-time surfacing†method revolutionized the welding of bogie beams. Previously, manual welding was time-consuming and imprecise, requiring frequent cleaning and repositioning. With robot programming, the welding becomes highly accurate, with fixed positions and no interruptions. This automation reduced welding time from 3–4 shifts to about 30 hours, boosting efficiency by nearly four times. The cost savings were enormous.
**Robots Navigating Tight Spaces**
CRRC Sifang Co., Ltd. operates China's first automatic welding flexible production line. However, during development, a complex weld trajectory in the narrow space of the side beam caused issues. The robot couldn’t accurately locate the area, leading to poor welds and excessive defects detected by ultrasonic testing. Even foreign experts struggled to solve the problem, causing delays in the production line.
Liu Jianshu stepped in and reprogrammed the system. “The space was extremely tight—only 10 cm wide. It was semi-blind welding, with many welds hidden from view,†he says. Using his extensive experience, he carefully mapped out each weld path, adjusting speed to avoid errors. After eight days of overtime, he achieved the difficult programming, impressing foreign experts. Now, the side beam is fully automated, with a 100% quality inspection rate. The defect rate from ultrasonic testing dropped from 5% to 0.3%.
**Liu Jianshu, the Electric Welder, Wins First Prize at CRRC**
Many would be surprised to learn that Liu, who only graduated from high school, solved problems that even foreign experts found challenging. His success came from self-study, reading foreign documents, and combining theory with practice. He credits the growth of high-speed rail and the support from his company for his achievements.
Since 2010, robots have handled over 80% of the critical welds on the bogie. Liu has also focused on training others. His three apprentices can now handle some programming tasks independently. “Programming requires patience and hands-on experience,†he says. “Only through years of work can you gain the insight needed.â€
His dedication has earned him recognition. In 2015, he received the Qingdao Model Worker award and won the Locomotive Medal as a core member. In 2016, the project “Flexible Welding Manufacturing Technology for High-Speed Train Steering Frame†won the first prize in CRRC Science and Technology.
Dongguan City Yuanyue Electronics Co.Ltd , https://www.yyeconn.com