Yaskawa develops new robot welding method with Toyota—Cutting roll cage production from weeks to days

On March 13, Yaskawa Electric held a press event in Toyota City, Aichi Prefecture, to introduce its new arc welding method using industrial robots: Sequence Freezing Arc-Welding (SFA). Developed jointly with Toyota Motor Corporation, SFA has been applied to the protective roll cages used in racing cars, reducing production time from two to three weeks to just two to three days. 

Stable and precise welding with robots 

Demonstration of robotic roll cage welding using the SFA method

During the March 13 press event, Yaskawa Electric demonstrated the SFA method using actual equipment. Co-developed with Toyota, the project began in January 2024, and the technology was unveiled in a vehicle at the “Super Taikyu Series” race held in Suzuka, Mie Prefecture, in September of the same year. 

SFA is a new robotic arc welding technology designed to improve roll cage rigidity and reduce production time. Compared to conventional robotic welding, SFA operates at a slower speed, which reduces heat distortion and enables high-precision welding. By alternating between high and low heat input, the method produces thin, uniform weld beads (weld lines) that increase joint rigidity.

Another key feature is the ability to weld gaps of around 2 mm while maintaining consistent quality—even when welding from below or at an angle. 

From three weeks to just three days 

SFA forms thinner and more uniform weld beads compared to other methods (from top: manual welding, conventional robotic welding, SFA welding)

Roll cages typically consist of about 50 pipe segments, which traditionally required skilled welders to join them manually, one by one. Because of the technical difficulty, it often took two to three weeks to complete a single roll cage. 

However, motorsport events such as races and rallies take place every month. If a roll cage was damaged in a crash, the vehicle would not be ready in time for the next event. SFA solves this problem by dramatically reducing production time to just two or three days, while also increasing rigidity. 

Manabu Okahisa, Senior Executive Officer and General Manager of the Robotics Division at Yaskawa Electric, explained, 

“SFA is a new welding method that uses robots to replicate the movements of skilled welders.  While improving productivity is one benefit, we gave top priority to improving the quality of roll cages.” 

Yaskawa and Toyota plan to further develop the technology so that robots can autonomously adjust welding speed based on real-time conditions—moving closer to replicating the expertise of human welders.